Heated underlayments are utilized in various construction industries. For instance, radiant in-floor heating systems typically utilize hot fluids circulating through tubes (hydronic systems) or electric current through cables (electrical resistance systems) installed in concrete slabs or attached to a subfloor and covered with a pourable floor underlayment. Hot fluids circulating through the tubes or electrical resistance in the cables warm the underlayment and the floor covering above. In roofing applications, heated panels are sometimes disposed beneath shingles or roofing panels to allow for heating the overlying roof surface in order to remove ice.